Circular fixator system and method

ABSTRACT

A device includes a plurality of rings. Each ring has a first face, a second face, and at least one slot defined by first and second interior edges of the ring on opposing sides of the slot. The at least one slot penetrates from the first face to the second face. The first face of each ring has a first recess adjacent the slot on the first edge and a second recess adjacent the slot on the second edge. A plurality of posts join each one of the plurality of rings to an adjacent one of the plurality of rings.

This application is a national phase entry under 35 U.S.C. § 371 ofinternational patent application no. PCT/US2016/055747, filed Oct. 6,2016 which claims the benefit of priority of U.S. Provisional PatentApplication No. 62/254,489, filed Nov. 12, 2015, all of which areexpressly incorporated herein by reference in their entireties.

FIELD

This application pertains generally to medical devices, and moreparticularly to a circular fixator.

BACKGROUND

For most standard triple arthrodesis procedures, a prebuilt frameincluding two tibial rings and a foot plate with an extension can beutilized. A Circular Fixator system can be used for open or closedfracture fixation, pseudoarthrosis or nonunions of long bones, limblengthening by epiphyseal or metaphyseal distraction, correction of bonyor soft tissue deformities, or correction of segmental or nonsegmentalbony or soft tissue defects. Circular Fixators have been used on longbones including: the tibia, fibula, femur, humerus, radius and ulna.

Prior to insertion of wires or pins, the circular fixator is positionedaround the tibia and foot. The leg is eccentrically located in the frameto accommodate the posterior musculature, and the plantar aspect of thefoot extends above or below the foot plate. To maintain the tibia andfoot in position, folded up towels can be placed under the calf.

The surgeon inserts wires through the bones, and secures the wires tothe frame using bolts that are inserted into holes in the rings and footplate of the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of a circular fixator according to someembodiments.

FIG. 1B shows a patient's leg positioned in the circular fixator of FIG.1A.

FIG. 1C shows the patient's leg fixed in the circular fixator of FIG.1A.

FIG. 2A is a plan view of the circular fixator of FIG. 1A.

FIG. 2B is a posterior side elevation view of the circular fixator ofFIG. 1A.

FIG. 3 is a side elevation view of the circular fixator of FIG. 1A.

FIG. 4A is an isometric view of a variation of the circular fixator ofFIG. 1A having recess pockets (without scallops).

FIG. 4B is a plan view of the device of FIG. 4A.

FIG. 5 is an isometric view of one of the fixation elements of FIG. 1C.

FIG. 6 is a side elevation view of the fixation element of FIG. 5.

FIG. 7 is an isometric view of an embodiment of the fixation elementfurther including a post.

FIG. 8 is a front elevation view of the fixation element of FIG. 7.

FIG. 9 is a cross sectional view taken along section line 9-9 of FIG. 8.

FIG. 10 is an enlarged detail of FIG. 9.

FIGS. 11A and 11B are isometric and plan views of a medial-lateral footsupport shown in FIG. 1A.

FIGS. 12A and 12B are plan and side views of another embodiment of amedial-lateral foot support suitable for use with the circular fixatorof FIG. 1A.

FIG. 13 is an isometric view of a mounting device for the foot supportshown in FIG. 11.

FIG. 14 is an isometric view of a medial-lateral leg support shown inFIG. 1A.

FIG. 15 is an isometric view of an anterior leg positioner shown in FIG.1A.

FIGS. 16A and 16B are left and right side elevation views of the legpositioner shown in FIG. 15.

FIGS. 17-19 are isometric, left side and anterior elevation views of thepositioner body shown in FIG. 15.

FIGS. 20 and 21 are isometric and posterior elevation views of one ofthe support devices shown in FIG. 15.

FIG. 22 is an isometric view of a wire drill guide for inserting thewires shown in FIG. 1C, with the tip extended.

FIGS. 23-25 are front, side and top plan views of the wire drill guideshown in FIG. 22.

FIG. 26 is a cross sectional view taken along section line 26-26 of FIG.25.

FIG. 27 is an exploded view of a second embodiment of the wire drillguide with combined tip and socket.

FIG. 28 is a side elevation view of the wire drill guide of FIG. 27.

FIG. 29 is an exploded view of a third embodiment of the wire drillguide with combined barrel and socket.

FIG. 30 is a side elevation view of the wire drill guide of FIG. 29.

FIG. 31 is an isometric view of the plug shown in FIG. 1B.

FIG. 32 is a cross sectional view of the plug of FIG. 31.

FIGS. 33 and 34 are isometric and plan views of a wrench used to tightenthe fixation elements and pin of FIG. 1C.

FIGS. 35 and 36 are front and rear isometric views of a clip forsecuring a sponge to one of the wires or rods of FIG. 1C.

FIG. 37 is a front end view of the clip of FIG. 35.

FIG. 38 is a rear end view of the clip shown in FIG. 36.

FIG. 39 is a top plan view of the clip shown in FIG. 35.

FIG. 40 is a cross sectional view taken along section line 40-40 of FIG.39.

FIG. 41 is a side elevation view of one embodiment of a rocker plate,according to some embodiments.

FIG. 42 is a plan view of the rocker plate shown in FIG. 41.

FIG. 43 is a side view of the rocker plate shown in FIG. 41.

FIG. 44 is a side elevation view of a slider, according to someembodiments.

FIG. 45 is a side view of the slider shown in FIG. 45.

FIG. 46 is a plan view of the rocker plate having a plurality ofcounterbores formed therein, according to some embodiments.

FIG. 46 is a side elevation view of the rocker plate of FIG. 46 coupledto a circular fixator, according to some embodiments.

DETAILED DESCRIPTION

This description of the exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. In the description, relativeterms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,”“below,” “up,” “down,” “top” and “bottom” as well as derivative thereof(e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should beconstrued to refer to the orientation as then described or as shown inthe drawing under discussion. These relative terms are for convenienceof description and do not require that the apparatus be constructed oroperated in a particular orientation. Terms concerning attachments,coupling and the like, such as “connected” and “interconnected,” referto a relationship wherein structures are secured or attached to oneanother either directly or indirectly through intervening structures, aswell as both movable or rigid attachments or relationships, unlessexpressly described otherwise.

The present disclosure provides circular fixators comprising rings witha plurality of slots for attachments of fixation devices. The fixationdevices fix the wires that inserted into the patient's leg and/or foot,for example. The circular fixator can be used for other extremities withdifferent variations of the structures as described herein. In someembodiments, the fixation devices include bolts with side slots, forreceiving the wires. The fixation devices can be pre-assembled andpre-loaded onto the circular fixator (e.g., by a scrub technician) priorto the arrival of the surgeon in the operating room. After inserting thewire, the surgeon can quickly and easily slide the pre-loaded fixationdevice into position for capturing the wire in a side slot of thefixation device. In some embodiments, the rings have recesses. Therecesses can include receptacles such as scallop-shaped recesses, curvedrecesses, V-shaped recesses, rectangular, semi-hexagonal,semi-octagonal, or recess pockets on both sides of the slots, andrecesses adapted to receive the fixation devices, and prevent them fromslipping in the tangential direction when the surgeon applies tension tothe wires for compression or distraction of joints or fractures. In someembodiments, the fixation devices include washers adapted to fit inrespective recesses. The fixation device is configured to fit in thereceptacle. In some embodiments, at least one edge of the fixationdevice can be received by the receptacle, even though the shape of thefixation device is different from the shape of the receptacle. Forexample, a rectangular receptacle can receive a hexagonal fixationdevice, and two sides of the receptacle will engage two opposite sidesof the hexagonal fixation device to prevent slippage.

In some embodiments, one or more of the fixation devices include postsfor providing an offset between the plane of the ring and the fixationbolt. In some embodiments, the posts have horizontal grooves and thewasher has a ridge for engaging one of the grooves of the post, toprevent the bolt from slipping on the post. In some embodiments, theposts are adapted to fit in the recesses.

In some embodiments, leg positioners are provided for supporting the legand foot in a neutral position or other desired position during theprocedure. In some embodiments, the leg positioners can be positionedand affixed to the circular fixator quickly and easily without using anytools, and the leg positioners have support elements, which can bequickly and easily adjusted without using tools for positioning the leg.

FIG. 1A is a an isometric view of a circular fixator 100 according tosome embodiments of this disclosure. FIG. 1B shows the circular fixator100 of FIG. 1A with a patient's foot drawn in phantom to show anexemplary use of the circular fixator for positioning the leg prior toand during the fixation procedure. FIG. 1C shows the circulator fixator100 with the patient's foot fixed by wires 412, following theprocedures. FIGS. 2A, 2B and 3 show plan, rear elevation and sideelevation views of the circular fixator 100.

The circular fixator 100 is a device comprising a plurality of rings102, 130 and 142. In some embodiments, one ring 102 of the plurality ofrings is elongated. The elongated ring 102 has a proximal portion 102 aand a distal portion 102 b. The elongated ring 102 is configured so thatthe distal portion 102 b can be rigidly attached to the first portion102 a in a first position parallel to or coplanar with the proximalportion 102 a. As shown in phantom in FIG. 3 the distal portion 102 bcan be rigidly attached to the first portion 102 a in a second positionhaving a non-zero angle with respect to the proximal portion. In someembodiments, the non-zero angle is 90 degrees.

In some embodiments, the plurality of rings include first and secondcircular rings 142, 130 adapted to be positioned around a leg of apatient during fixation, and the first ring 142 is greater in diameterthan the second ring 130 and 102. This configuration permits the surgeonto maintain a constant distance. As a general rule of thumb, theclearance between the inner diameter of each ring and the nearest legtissue is about two fingers' breadth (e.g., about 3.7 cm to about 4 cm),at different heights along the patient's leg. Similarly, if the fixatoris adapted for use on another extremity, a similar clearance between theinner diameter of each ring and the nearest tissue is used. Because thepatient's calf is greater in diameter further from the ankle, the topring 142 is correspondingly greater in inner diameter than the middlering 130. Because the ring 130 is smaller, it reduces the moment arm forpins or wires. For example in one embodiment, the top ring 142 has aninner diameter of about 18 cm, and the middle ring 130 has an innerdiameter of about 16 cm. This is just one example, and any combinationof ring sizes can be used to accommodate the geometry of any givenpatient's calf.

Each ring 102, 130 and 142 has a first (e.g., top) face, a second (e.g.,bottom) face, and at least one slot. For example, ring 102 has slots104, 110, 116, 122; ring 130 has four slots, including slots 132, 138;and ring 142 has slots 144, 150, 154, and 160. Each slot is defined byfirst and second interior edges of its respective ring 102, 130 and 142on opposing sides of the slot. Each slot (e.g., 104) penetrates from thefirst face of the ring (e.g., 102) to the second face. The first (e.g.,top) face of each ring (e.g., 102) has a first scallop-shaped recess(e.g., 106 a) adjacent the slot 104 on the first edge and a secondscallop-shaped recess (e.g., 106 b) adjacent the slot 104 on the secondedge. The slot 104 terminates at an opening 108 a, 108 b at eachrespective end of the slot. The openings 108 a, 108 b have a dimensionthat is substantially greater than a width of the slot 106. Similarly,in the example of FIG. 1, slot 110 has scallop-shaped recesses 112 a,112 b and end openings 114 a, 114 b; slot 116 has recesses 118 a, 118 band end openings 120 a, 120 b; slot 122 has recesses 124 a, 124 b andend openings 126 a, 126 b; slot 132 has recesses 134 a, 134 b and endopenings 136 a, 136 b; slot 138 has recesses 140 a, 140 b and endopenings 141 a, 141 b; slot 144 has recesses 146 a, 146 b and endopenings 148 a, 148 b; slot 150 has recesses 151 a, 151 b and endopenings 152 a, 152 b; and slot 160 has recesses 162 a, 162 b and endopenings 164 a, 164 b.

In other embodiments, instead of a scallop-shaped recesss 134 a, 134 b,146 a, 146 b, one or more of the rings include recess pockets, asdescribed below with reference to FIGS. 4A and 4B. In some embodimentsthe circular fixator includes at least one ring 102 having scallopshaped recesses 106 a, 106 b, 112 a, 112 b, 118 a, 118 b, and at leastone ring having recess pockets, as described below in the discussion ofFIG. 4A.

FIGS. 4A and 4B show a variation of the circular fixator 700. In someembodiments, the circular fixator 700 includes the same bottom ring 102as described above, with scalloped recesses on each side of each slot.The scallops provide additional protection against slippage of thefixation device, for example when tensioning a wire to compress ordistract a joint. In some embodiments, the middle ring 702 has slots 712with recesses 714 a, 714 b (without scallops) on each side of the slots712. Similarly, the top ring 704 has slots 716 with recesses 718 a, 718b (without scallops) on each side of the slots 712. In many procedures,the surgeon does not require compression or distraction of the foot orleg at the levels of the middle ring 702 or the top ring 704. Theserings 702, 704 stabilize the leg. The rings 130, 142 with scallops canbe used at the upper levels of the leg as described above with referenceto FIGS. 1-3.

However, if the upper and middle ring are only used for stabilization,the rings 702, 704 without the scallops may permit the fixation device300 to move toward the wire more quickly without any chance of becomingcaught in a scallop. Additionally, the recesses 714 a, 714 b, 718 a, 718b without scallops allow the surgeon to fix the fixation device 300anywhere along the length of the slots, and the surgeon is not limitedto any discrete set of fixed locations.

When the wire is run perpendicular to the slots 712, 716, there islittle chance that the fixation device 300 can slip in the slot. If thewires are to be run perpendicular or nearly perpendicular to the slots,the surgeon may prefer that the rings 702, 704 (without scallops) areused for ease of use. On the other hand, the greater the angle betweenthe wires and the slots, the greater the benefit of the scallops, forpreventing slippage.

In other embodiments (not shown), all three rings 102, 702, 704 can beprovided without scallops.

The reference numerals of other features of the circular fixator ofFIGS. 4A and 4B which are the same as the corresponding items shown inFIG. 1A are omitted for ease of understanding, and their descriptionsare not repeated.

The device further includes a plurality of posts 270 joining each one ofthe plurality of rings 130, 142 to an adjacent one of the plurality ofrings. In some embodiments, the center ring 130 is connected to the topring 142 by fixed posts 270, and the center ring 130 is connected to thebottom ring 102 by a plurality of calibrated struts 260. The calibratedstruts permit accurate and even adjustments to the distance between thebottom ring 102 and the center ring 130 (e.g., forcompression/distraction of the foot or height adjustments to the desiredheight). In some embodiments, all of the posts 270 are of the same fixedtype (as shown in FIG. 4A). In some embodiments, as shown in FIG. 1A,one or more of the posts 270 can be replaced by suitably configuredplates 271, threaded rods, spacers, or struts. For example, the places271 can each have a respective vertical slot 272. Each slot 272 hasopenings 273 at the top and bottom of the slot. The slots 272 can havethe same width as the slots 112 a, 112 b, and the openings 273 can havethe same size as the openings 114 a, 114 b. The slots 272 of the plates271 can receive fixations elements 330, and the openings 273 can receiveplugs 170, for pre-loading the fixation elements 330, in the mannerdescribed below. In other embodiments, any combination of posts 270,plates 271, rods, spacers and/or struts can be used.

In some embodiments, each scallop-shaped recess (e.g., 112 a, 112 b)comprises a plurality of curved arcs, and each curved arc subtends anangle in a range from about 10 degrees to 170 degrees. In someembodiments, the subtended angle is in a range from 30 degrees to 150degrees. In some embodiments, the subtended angle is in a range from 30degrees to 150 degrees. In some embodiments, the subtended angle is in arange from 60 degrees to about 120 degrees. In some embodiments, eachscallop-shaped recess comprises a plurality of circular arcs, eachcircular arc subtending an angle of about 90 degrees. The arcs subtendan angle that is sufficiently large to resist slipping of any fixationdevice 330 (FIG. 5, described below) relative to the slot, particularlyif any force component is applied to the fixation device 330 parallel tothe direction of the slot (e.g., 110). In some embodiments, the rings102, 130, 142 comprise a metal, such as aluminum or titanium.

In some embodiments, at least one of the fixation devices 300 comprisesa bolt 330, a nut 334 and a washer 340. The bolt 330 has head 332 and athreaded portion 331 sized to fit through the slot (e.g., 112 a, 112 b).The bolt 330 includes a side slot 348 in a side surface of the threadedportion 331, for receiving a wire (FIG. 1C) The washer 340 is shaped tofit a respective one of the curved arcs on the scallop-shaped recess 114a, 114 b on each side of the slot 110 of the ring 102. In someembodiments, the washer 340 has a textured gripping surface 346 forsecurely positioning the wire. The washer 340 has two curved edges 343adapted for fitting the curved arcs of the scallop shaped recesses. Theremaining two edges of the washer can be flat. The gripping surface canhave ridges, barbs, splines, slots, a knurled surface, or the like. Insome embodiments, the opening (e.g., 114 a, 114 b) at each end of eachslot (e.g., 112 a, 112 b) is adapted to receive a nut 334 of a fixationdevice 330 through the opening. In some embodiments, the slot (e.g., 112a, 112 b) is adapted to receive a threaded portion 331 of the fixationdevice 330 through the slot, but the slot has a width that is smallerthan a dimension of the nut 334. Thus, once the nut 334 is affixed tothe threaded portion 331, the fixation device 330 can be inserted intothe openings (e.g., 114 a, 114 b) but cannot fall out of the slots. Thefixation devices can be pre-assembled, and the pre-assembled fixationdevices can pre-loaded onto the slots prior to surgery. The openings(e.g., 114 a, 114 b) can be then be plugged to prevent release of thefixation devices 330.

Some embodiments further comprise at least one post 302 (FIG. 7) havinga threaded body portion 314 adapted to fit through the slot (e.g., 110)of the ring 102. The post 302 has a longitudinal slot 307 (add todrawing) through the post (and parallel to the longitudinal axis of thepost) for receiving the bolt 330 of the fixation device 300. The post302 has a mounting surface 303 for engaging a respective one of thecurved arcs on the scallop-shaped recess (e.g., 112 a) on each side ofthe slot (110). In some embodiments, the mounting surface 303 of thepost 302 has two curved (e.g., circular) arc edges 310, adapted to bereceived in one of the curved arcs on the scallop-shaped recess. In someembodiments, the mounting surface 303 of the post 302 has two flat edges312, which can be gripped in the jaws of a wrench or other suitabletool. The post 302 allows the surgeon to position the bolt 330 of afixation device 300 at a height that is offset from the rings 102, 130,142.

As shown in FIG. 7, the post 302 has a plurality of grooves 306 on atleast one side face of the post, oriented perpendicular to the length(longitudinal axis) of the post. In some embodiments the opposite sidesurface 304 of the post 302 is flat, as shown in FIG. 8. In otherembodiments, both side faces of the post have grooves 306. The washer340 includes a ridge 342 adapted to engage one of the grooves 306. Thisprevents the bolt 330 from slipping relative to the post 302, particularwhen a component of the force applied to the bolt 330 is parallel to thedirection of the slot 307 of the post 302. In some embodiments, thewasher 340 is of the same type described above, and the ridge 342 isincluded on the face of the washer opposite the textured grippingsurface 346.

In some embodiments, the surgeon can also insert rods 350 into the boneusing the circulator fixator 100. A pin cube 351 (FIG. 1C) can bemounted in the slot (e.g., 154, FIG. 1C) for fixing the pin 350 (alsoreferred to as a rod).

In some embodiments, the surgeon tightens the bolts 330 using aratcheting wrench 600 (FIGS. 33 and 34) having an open socket that canslide over a threaded rod to tighten or loosen a bolt or nut. The wrenchhas a ratchet mechanism. In some embodiments, the ratchet mechanismincludes a switch pin biased against a gear 610 by a spring to act as apawl, to allow rotation in one direction. The wrench body 601 has anopen end 605, and the rotating socket 602 has an open end 603. To placethe wrench in position on the rod, the open end 603 of the socket isaligned with the open end 605 of the wrench body, as shown in FIGS. 33and 34. This wrench configuration is particularly useful for tighteningor loosening threaded rod, bolts and nuts.

In other embodiments (not shown), the switch pin is omitted. Thedirection of rotation of the wrench is fixed for applying torque onlywhen rotated in one direction. A spring-biased piston with a beveledpiston surface acts as a pawl that engages the gear 610 of the hexagonalsocket 602 to allow one-way rotation of the hexagonal socket. The wrench600 is oriented with one side facing upwards to apply torque fortightening bolts 330, and with the other side facing upwards to applytorque for loosening the bolts. In some embodiments, indicia are placedon the wrench, so the user can quickly determine which side of thewrench should face upwards for any given tightening or loosening step.

In some embodiments, as shown in FIGS. 31 and 32, the device furthercomprises a plurality of detachable plugs 170. Each plug 170 has a shapeand size adapted to be detachably retained in a respective one of theopenings (e.g., 114 a), for retaining the bolt 330 in the slot 110 priorto tightening the nut 334 and bolt 330. Each plug 170 has a compressibletubular end 176 and a ridge 180 for retaining the plug within arespective one of the openings 114 a. The scrub technician can quicklyand easily insert one of these plugs in each opening 114 a, 114 b of aslot 110 for retaining pre-assembled, pre-loaded fixation devices 330,posts 300, or pin cubes on the circular fixator.

In some embodiments, the plug 170 includes a gripping portion 172, whichmay include a gripping surface 174, such as a contoured portion. Theplug 170 further includes a plug portion 176, which is shaped to fit theopenings (e.g., 114 a, 114 b) at the end of each slot. For a circularopening (e.g., 114 a), the plug portion 176 is generally shaped as acircular cylinder. The plug portion 176 further includes a plurality ofslots 178 oriented in the longitudinal direction. For example, the plugportion 176 may have four slots evenly spaced about the circumference ofthe plug portion 176. The plug portion 176 further includes a ridge 180for retaining the plug 170 in the opening 114 a. The ridge is greater indiameter than the opening 114 a. The slots 178 permit the members of theplug portion 176 to be squeezed together for insertion into, or removalfrom, the openings. The plug is made of a plastic materials such asacrylonitrile-butadiene-styrene (ABS).

In some embodiments, a plurality of leg positioners hold the patient'sleg in a neutral position while the surgeon inserts wires and/or rods inthe leg. The leg positioners generally include at least one Y-shapedmember (or round or curved member) having a concave or angled portionfor supporting a limb of a patient, and a mounting device for attachingthe positioner to one of the plurality of rings without a tool.

FIGS. 1 and 11A-11B show an example of a medial-lateral leg positioner230, in which the Y-shaped member 230 includes a support arm 231 havinga slot 235 through the arm. An angled support member 233 is attached tothe arm 231. The leg positioner 230 can be attached to or detached fromthe ring 102 without using any tool.

FIGS. 12A and 12B show another example of a medial-lateral legpositioner 261, having a support arm 262 and a support member 263. Thesupport member 263 is asymmetrical, and includes an extended cup-shapedmember 265 configured to extend under and support the foot. The extendedmember 265 can be curved or angled. In some embodiments, the extendedmember 265 ends in a substantially flat portion 267. The other portion264 of the support member 263 can be flat or curved, and can be similarto the member 233 in FIG. 11A. The support arm 262 has a slot 2266through the arm. The leg positioner 230 can be attached to or detachedfrom the ring 102 without using any tool.

In some embodiments, the leg positioner 230 is attached to the ring 102by a mounting device 257 (FIG. 13) comprising a threaded member 256adapted to fit through the slot (e.g., 110) of one of the plurality ofrings 102 and through the slot 235 of the support arm 231simultaneously, for attaching the arm 231 to the ring 102. The threadedmember 256 has a head 254 at one end. The head 254 has a width W1smaller than a width of the slots 110 of the rings, and a length L1greater than the width of the slots 110 of the ring 102. The length isselected so that the head can engage one of the curved arcs of thescallop-shaped recesses 112 a, 112 b on each side of a slot 110 of oneof the plurality of rings 102.

In some embodiments, the mounting device 257 further includes a threadedknob 252 configured so that it can optionally be received in one of thecurved arcs of the scallop-shaped recess 112 a of the one of theplurality of rings 102 (although the knob 252 can be located in otherpositions. The threaded knob 252 is configured for receiving thethreaded member 256 of the mounting device 257. The threaded knob 252has a size that is greater than a width of the slots 110 of the rings,but smaller than the dimension of the openings 114 a, 114 b. Thus, themounting device can be pre-assembled to the Y-shaped member 230, and theknob can then be passed through the opening 114 a, 114 b to install theleg positioner 230 on the ring 102. Alternatively, the pre-assembledmounting device 257 can be installed on the ring by orienting the head254 parallel to the slot 110, and passing the head 254 through the slot110.

FIG. 14 shows another leg positioner 250 suitable for attachment to thetop ring 142, in which the Y-shaped member 250 includes a support arm251 having a slot 255 through the arm. An angled support member 253 isattached to the arm 251. The leg positioner 250 can be attached to thering 142 using the same type of mounting device 257 described above (andshown in FIG. 13), and for brevity, a description of the mounting deviceis not repeated. The threaded member 256 of mounting device 257 isadapted to fit through the slot (e.g., 110) of one of the plurality ofrings 102 and through the slot 255 of the support arm 251simultaneously, for attaching the arm 251 to the ring 130 or 142.

These are just two examples of the leg positioner. In other embodiments,the support member 233 and/or 253 can have a different angle. In otherembodiments, the support member 233 and/or 253 can have a concave curvedshape.

FIGS. 15-21 show another type of leg positioner 200 suitable forsupporting two different portions of the leg at two different heightssimultaneously. FIGS. 15, 16A and 16B are isometric, right side, andleft side elevation views, respectively, of the leg positioner assembly200. FIGS. 17-19 are isometric, side elevation and front elevation viewsof the body 201 of the assembly 200. FIGS. 20 and 21 are isometric andrear elevation views of the top leg positioner 212 of FIG. 15.

Leg positioner 200 includes a plurality of independently positionablesupport devices 204, 206 for supporting a limb of a patient. Supportdevice 204 has a respective arm 207 and a respective concave or angledportion 208 attached to the arm 207, for supporting the heel. Supportdevice 206 has a respective arm 207 and a respective concave or angledportion 212 attached to the arm 207, for supporting the calf. Thepositions of the support devices 204, 206 can be switched by the surgeonor technician, if desired.

Leg positioner 200 includes a body 201 having a plurality of openings203 for slidably receiving respective ones of the plurality of supportdevices 204, 206 through the openings 203. In some embodiments, thesupport devices 204, 206 are of the same type as each other. In someembodiments, the support devices 204, 206 are of different types fromeach other (i.e., include different concave or angled portions). Inother embodiments, the support devices 204, 206 are of different sizesand/or different types.

In some embodiments, the concave or angled portion 212 of at least oneof the support devices 206 has a plurality of slots 214 a, 214 b forreceiving a retaining strap (not shown) therethrough. For example, thetechnician or surgeon can optionally run a Velcro strap through theslots 214 a, 214 b and wrap the strap around the patient's leg.

The leg positioner 200 also includes a respective retaining device 209,215 proximate each respective openings 203, for retaining a respectiveone of the support devices 204, 206 in a continuously selectableposition.

The leg positioner 200 further includes a mounting device 218 fordetachably mounting the leg positioner to an edge of one of theplurality of rings. For example, as shown in FIG. 1A, the leg positioner200 can be attached to the bottom ring 102.

As best seen in FIGS. 17-19, the body 201 has a first opening 203. Thefirst opening 203 includes a passage 203 p (FIG. 19) penetratingcompletely through the body 201 from a first face 201 a of the body 201to a second face 201 b opposite the first face, and a relatively narrowslot 205 extending from the passage 203 p to a side edge 201 e of thebody. The slot 205 has a height H2 that is less than a height H1 of thefirst opening 203.

As shown in FIGS. 15, 16A, 20 and 21, each support device (also referredto as a leg positioning element) 204 (206) comprises an arm 207 adaptedto slidably fit in the first opening 203 for sliding along a firstdirection X normal to the first face 201 a. A support 208 (212) isadapted to support a first portion of a limb of a patient. A neckportion 207 n connects the support 208 (212) to an end of the arm 207.The neck portion 207 n is adapted to slidably fit in the slot 205, topermit removal of the leg positioning element 204 (206) from the body201 through the slot 205 in a second direction Y parallel to the firstface 201 a. When the support device 204, 206 is advanced in the Xdirection, so the retaining members 221 engage the arm 207, the supportdevice 204, 206 is constrained from moving in the Y direction.

Referring now to FIG. 16B, the body 201 has a first and second retainingmembers 221 defining the slot 205 therebetween. The retaining members221 have a depth 221 d in the first direction (X) that is less than adepth 201 d of the body 201 in the first direction. The length of theneck portion 207 n is greater than the depth 221 d of the retainingmembers 221, and is sufficiently long so that the end of the arm 207 canbe backed out (in the −X direction) until the neck 207 n is alignedbetween the retaining members 221, and can be moved in the Y directionthrough the retaining members 221. In some embodiments, the neck portion207 n has a length LN (FIG. 20) that is less than the depth 201 d of thebody 201 in the first direction X. FIG. 16B shows the positioner 200with both support devices 204, 206 in the fully retracted position(wherein the concave or angled portions 208, 212 abut the first face 201a of the body 201. In this position, the neck portions 207 n arepositioned between the retaining members 221, to permit the supportdevices 204, 206 to be removed from the body by sliding the supportdevices in the Y direction, through the slot 205 between the retainingmembers 221. Conversely, when the arms 207 are extended so the concaveor angled portions 208, 212 do not abut the first face 201 a of the body201, the arms 207 can slide in the X direction, but cannot move in the Ydirection.

In some embodiments, when the surgeon completes insertion of wiresand/or pins, the leg positioner assembly 200 can be removed easily byfully retracting each of the support devices 204, 206, and sliding thesupport devices in the Y direction relative to the body 201 of the legpositioner assembly 200 (or sliding the body 201 relative to the supportdevices 204, 206). Thus, the leg positioner assembly 200 can be removedwithout disturbing the position of the leg relative to the frame 100.

The leg positioner 200 further includes a first locking device 209 (215)for locking the arm 207 in a fixed position relative to the body 201without using a tool. For example, as shown in FIG. 15, the lockingdevice 209 (215) can be a screw including an enlarged head for grippingand advancing the screw without a tool.

Some embodiments further comprise a mounting device 218 for mounting thebody to the circular fixator 100 without using a tool. For example, body201 has two jaws 216, 217 spaced sufficiently far apart to receive anedge of one of the rings 102, and a screw 218 which penetrates thebottom jaw 216.

FIGS. 23-26 show a wire drill guide 400 for inserting wires 412 to fixthe patient's leg to the frame 100. The drill guide 400 is adapted foruse with both smooth wire (not shown) and olive wire 412 (having anolive structure 413). FIG. 22 is an isometric view, and FIG. 24 is aside elevation view. FIG. 23 is a front elevation view of the wireinsertion tip 406 shown in FIGS. 22 and 24. FIG. 25 is a top plan view,and FIG. 26 is a cross-sectional view taken along section line 26-26 ofFIG. 25. FIG. 26 includes the ring 102 of circular fixator 100 and awire 412 having an olive structure 413 for reference. The ring 102, wire412 and olive structure 413 are not part of the drill guide 400 but areincluded in FIG. 26 for ease of understanding the use of the wire drillguide 400.

The drill guide 400 includes a barrel 401, through which the wire 412can be run. The barrel 401 is generally in the form of a hollow,half-cylindrical shell, with flat edges 401 b on the bottom thereof. Ahandle 402 is provided at the rear end of the drill guide 400. The frontend of the barrel 401 has a rearward extending finger 404. With the flatedges 401 b of the barrel resting on the top or bottom surface of one ofthe rings 102, 130, 142, the rearward extending finger 404 wraps aroundunder the inner edge of the ring (e.g., 102), to provide stability whilethe surgeon inserts the wire 412. For example, in FIG. 26, across-section of the ring 102 is shown in phantom. By positioning thedrill guide 400 relative to the inner edge of the ring 102 as shown, thedrill guide 400 is stably directed radially inward toward the patient'sleg.

As shown in FIG. 26, the barrel 401 has a proximal guide portion 410with an inlet opening 409 therein at the rear of the barrel. The opening409 of the proximal guide portion 410 is larger in diameter than theolive structure 413. The passage 410 and inlet 409 are larger than theolive 413 of a standard olive wire 412, permitting the olive to beinserted through the inlet 409. The barrel 401 also includes an outletpassage 411 which is larger in diameter than the olive 413.

The drill guide 400 further comprises a tip 405 having a centrallongitudinal passage 407. The passage 407 is greater in diameter thanthe wire 412 (e.g., K-wire), but smaller in diameter than the olive 413.(Although an example is described herein using olive wire, the samedrill guide 400 can also be used with smooth wire.) The tip 405 has aslot 406 extending in the radial direction from the passage 407 all theway to the exterior surface of the tip, as best seen in FIGS. 22 and 24.Thus, if an olive wire 412 is inserted through the barrel 401 and theoutlet passage 411, and advanced until the olive 413 is within or nearthe tip 405, the tip 405 of the drill guide 400 can be removed bypassing the slot 406 of the tip over the front portion 412 f of the wire412. The remaining portions of the drill guide 400 can then be backedoff over the olive 413, and the rear portion of the wire 412 (distalfrom the patient) is fixed to the frame 100 by the fixation element 330.The drill guide can be made of 630 stainless steel, for example.

The method of using the drill guide 400 for inserting at least one wire412 includes placing a drill guide 400 on a ring 102 of the circularfixator 100, so as to direct the at least one wire 412 towards a bone ofthe patient, where the drill guide 400 has a longitudinal opening 407adapted to pass the at least one wire 412 therethrough (but not largeenough to pass the olive 413 therethrough). The surgeon or technicianholds the handle 402 to position the drill guide 400. The surgeon drivesthe at least one wire 412 through the longitudinal opening 407 andthrough the bone.

In some embodiments, the drill guide 400 has a flat surface 401 b and afinger 404 for wrapping around a proximal edge of the ring 102, and thestep of placing the drill guide 400 includes positioning the drill guideso that the flat surface 401 b engages a top or bottom face of the ring102. The barrel is sized to be long enough (or angled) to permit thesurgeon to slide the drill guide 400 forward until the tip 405 contactsthe bone for precise drilling.

In other embodiments of the method, the surgeon can position the drillguide 400 under the ring 102, so that the flat surface engages a bottomface of the ring, and the finger 404 wraps around the top surface of thering.

In some embodiments, the drill guide 400 has a proximal guide portion410 with an opening 409 therein, the opening of the proximal guideportion larger in diameter than the olive structure 413. The step ofdriving the at least one wire 412 further comprises passing the olivestructure 413 through the opening 409 of the proximal guide portion 410.

In some embodiments, the drill guide 400 has a removable tip 405 with aslot 406 therein and a front opening 407 for feeding the wire 412therethrough. The wire 412 has an olive structure 413 larger than thefront opening 407. The step of driving the at least one wire 412includes driving the wire 412 until the olive structure 413 is within ornear the tip 405, and removing the tip 405 of the drill guide 400 bypassing the slot 407 of the tip over the wire 412.

In some embodiments, a socket 414 (collar) receives the front end of thebarrel 401 and the rear end of the tip 405. In some embodiments thesocket 414 has slots to provide sufficient compliance that the socket414 can snugly receive the front end 416 of the barrel and the rear endof the tip 405. In some embodiments, the length of the front end 416 andthe length of the socket 416 are selected to provide allow the socket414 to slide part of the length of socket forward to extend the lengthof the drill guide (in the position shown in FIG. 22). Alternatively,the drill guide can be included in a kit having a plurality of sockets414 of different lengths.

FIGS. 27 and 28 are isometric and side cross sectional views of anotherembodiment of the drill guide 400-2, in which the barrel 401 and socket415 are integrally combined in one unitary piece. The remaining elementsof drill guide 400-2 are the same as for the drill guide 400, asindicated by like reference numerals, and descriptions of these elementsare not repeated for brevity. The operation and use of the drill guide400-2 is the same as described above with reference to FIGS. 23-26, andthe description is not repeated, for brevity.

FIGS. 29 and 30 are isometric and side cross sectional views of anotherembodiment of the drill guide 400-3, in which the tip 425 and socket 427are integrally combined in one unitary piece. The tip 425 includes acentral passage 427 having a front opening, and a radial slot 426connecting the central passage 427 to the outer surface of the tip 425.The socket receptacle 428 receives the front end 416 of the drill guidebarrel 401. The remaining elements of drill guide 400-2 are the same asfor the drill guide 400, as indicated by like reference numerals, anddescriptions of these elements are not repeated for brevity. Theoperation and use of the drill guide 400-3 is the same as describedabove with reference to FIGS. 23-26, and the description is notrepeated, for brevity.

FIGS. 35-40 show a sponge clip which can be used during any of thefixation procedures described herein (e.g., Charcot fixation procedure).The clip comprises a body 500 having a longitudinal axis 520 (shown inFIG. 40, and coinciding with section line 40-40 in FIG. 39). The body500 has a tubular sidewall 511 integrally attached at a perimeter of thebody. The body 500 has a slot 501 extending parallel to the longitudinalaxis 520. The slot 501 penetrates the tubular sidewall 504 and extendspart way through the body 500.

The body 500 has first and second longitudinal tubular gripping surfaces503 and 504 within the slot 501. The second longitudinal tubulargripping surface 504 has an inner diameter that is different from aninner diameter of the first longitudinal tubular gripping surface 503.The slot 501 extends through each of the first and second longitudinaltubular gripping surfaces 503, 504. The gripping surface 503 is sized togrip a wire 412 (e.g., smooth 1.8 mm or 2 mm K-wire or olive wire), andthe gripping surface 504 is sized to grip a standard (4 mm, 5 mm or 6mm) half pin 350 (shown in FIG. 1C) of the type surgically insertedduring the procedure. (Pins 350 can be inserted in the anterior side ofthe tibia or in the calcaneus, but wires 412 are used elsewhere. Wirescan also be used in the tibia and/or calcaneus.) By inserting the wire412 or pin 350 into the slot 501 and placing the gripping surface 503around the wire 412 (or the griping surface 504 around the pin), theclip is quickly attached to the pin 350 or wire 412 without any tools.The clip can be positioned close to the insertion site of the wire orpin, to retain a sponge or other absorbent material against the woundsite.

The body has first and second end surfaces 510, 511. The first endsurface 510 is perpendicular to the longitudinal axis 520, and thesecond end surface 511 is oriented at an oblique angle relative to thelongitudinal axis 520. The clip 500 can be attached to a wire 412 or pin350 perpendicular to the bone, with the first end surface 510 facingtoward the wound site, and the second end surface 511 facing away fromthe wound site. In this orientation, the first end surface 510 isparallel to the surface of the bone and holding a sponge against thewound site. Alternatively, the clip 500 can be attached to a wire 412 orpin 350 at an oblique angle with respect to the bone, with the secondend surface 511 facing toward the wound site, and the first end surface510 facing away from the wound site. In this orientation, the second endsurface 511 is parallel to the surface of the bone and holding a spongeagainst the wound site. Thus, by selecting which end of the clip 500 toplace closer to the wound site, the surgeon can maximize the area of theclip which engages the sponge (or other dressing) with the longitudinalslot 501 of the clip 500 aligned with the wire 412 or pin.

In some embodiments, the clip 500 has a counterbore 505 in the first endsurface 510, to relieve pressure on the wound site. In some embodiments,the clip 500 has a counterbore 518 in the second end surface 511. Thecounterbores 505, 518 can assist in retaining the sponge or otherdressing. In some embodiments, one or both of the counterbores 505, 518has reinforcing ribs 517.

In some embodiments, the first longitudinal tubular gripping surface 503is at or near the longitudinal axis 520, and the second longitudinaltubular gripping surface 504 is near a periphery of the body. In someembodiments, the second longitudinal tubular gripping surface 504 has adimension G2 perpendicular to the longitudinal axis 520 which is largerthan a dimension G1 of the first longitudinal tubular gripping surface503 perpendicular to the longitudinal axis 520.

In some embodiments, the clip has a flat surface 513 opposite theopening of the longitudinal slot 501, to permit the surgeon ortechnician to push the clip onto the wire 412 or pin. The flat surfacecan have a key 515 to provide flexibility to open and close the clip,and to retain the clip on the pin. The remainder of the body has a roundperimeter for ease of removal.

In some embodiments, the clip is formed from a single piece of aplastic, such as acrylonitrile-butadiene-styrene (ABS).

In some embodiments, a method for using the above-described apparatusfor positioning a leg of a patient comprises pre-loading respectivefixation devices 330, 302 in a plurality of slots (e.g., 110) of acircular fixator 100. Each fixation device 330 has a threaded bolt witha side slot 307 in a side edge thereof. The circular fixator 100includes at least one ring e.g., 102, having the plurality of slots(e.g., 110) extending therethrough. The ring 102 has a scallop shapedrecess 112 a, 112 b or recess pocket with a plurality of curved arcs oneach of two respective interior edges that define the slot 110therebetween. The fixation device 330 further includes a washer 340having peripheral edges 343 adapted to fit in a respective curved arcsof the respective recess 112 a, 112 b of each of the edges.Alternatively, if the user wants to put the fixation device 330 inbetween scallops, the user can turn the washer 340 sideways, to clearthe scallops.

Each threaded bolt 330 has a respective head 332 and a respective nut334, and at least one slot (e.g., 110) of the circular fixator 100 hasan opening 114 a, 114 b at each end thereof. The openings 114 a, 114 bhave a size larger than a size of the head 332. The pre-loading stepincludes: inserting the head 332 or nut 334 of one of the fixationdevices 330 though one of the openings 114 a, 114 b, so that the ring102 is between the head and the nut; and inserting a plug 170 in each ofthe openings 114 a, 114 b after inserting the head 332 or nut 334, toprevent the fixation device 330 from falling out of the ring 102.

In some embodiments, at least one leg positioner 200 is attached a to anposterior end of the circular fixator without using a tool before theposition step. In some embodiments, the leg positioner 200 includes aplurality of adjustable supports 204, 206, the method further comprisesindependently adjusting the position of each support 204, 206 withoutusing a tool, to accommodate the leg thereon.

Some embodiments include attaching leg positioners 230, 250 to thecircular fixator 100 on medial and lateral sides of a foot of thepatient without using tools, so as to support the foot in a neutral orother desired position, before inserting the at least one wire 412. Insome embodiments, each of the additional leg positioners 230, 250includes a mounting device 257 having a threaded member 256. The step ofattaching additional leg positioners comprises: placing the mountingdevice 257 so that the threaded member 256 of the mounting deviceextends through the slot (e.g., 138) of the ring 130 and a slot 235(255) in an arm 231 (251) of the leg positioner 230 (250), and the head254 of the mounting device 257 engages respective recesses (e.g., 140 a,140 b) in the ring 130 on opposite sides of the slot 138 of the ring130; and securing the mounting device 257 and the leg positioner 230,250 to the ring 130 with a nut 252.

The circular fixator 100 is positioned around the leg. In someembodiments, the circular fixator 100 has first and second circularrings 142, 130 adapted to be positioned around the leg of the patient.The first ring 142 is greater in diameter than the second ring 130, andthe positioning step includes: positioning the first ring 130 around afirst portion of the leg, and positioning the second ring 142 around asecond portion of the leg. The first portion of the leg has ananterior-to-posterior dimension that is greater than ananterior-to-posterior dimension of the second portion of the leg.

At least one wire 412 is inserted through leg after the pre-loading. Thesurgeon positions the wire drill guide 400 with the finger 404 engagingthe ring (e.g., 102) of the circular fixator 100) near the insertionsite, and directs the tip 405 inward toward the bone. The tip 405 can beextended to contact the bone. The surgeon inserts the wire 412. When theolive structure 413 reaches the passage 411, the tip 405 is removed, andthe drill guide 400 can be backed away from the insertion site.

Each pre-loaded fixation device is slid until the side slot 348 thereofengages the at least one wire 412. To permit this step, the pre-loadingincludes placing the threaded bolt 330 of one of the fixation devicesthrough the slot 110 of the circular fixator ring 102 with a nut 334attached to the bolt, so that the nut is sufficiently loose to permitthe sliding. The sliding step includes moving the one of the fixationdevices 330 until the peripheral edges 343 of the corresponding washer340 of the fixation device are received in respective curved arcs of therespective recess 112 a, 112 b of each of the edges.

In some embodiments, at least one of the fixation devices 330 includes apost 302 having a longitudinal slot 307 therethrough and a threadedmember 314, and the pre-loading includes: placing the threaded bolt 330of one of the fixation devices through a slot 307 in the post 302 ofthat fixation device, placing respective nuts 316 on the threaded member314 of the post 302 and the threaded bolt 330, and placing the fixationdevice 330 in the ring 102, so that the threaded member 314 of the postextends through the slot 110 of the ring 102, with the nut 316 on thethreaded member 314 of the post 302 sufficiently loose to permit thesliding. The ring 102 has a scallop shaped recess 112 a, 112 b with aplurality of curved arcs on each of two respective interior edges thatdefine the slot of the ring therebetween, the post 302 has a mountingsurface 303 configured to fit in a respective one of the curved arcs ofthe scallop-shaped recess 112 a, 112 b on each respective side of theslot 110 in the ring 102, and the step of sliding includes sliding thethreaded member 314 of the post 302 within the slot 110 until the sideslot 348 of the threaded bolt 330 engages the wire 412 and the mountingsurface 303 of the post 302 is received by a pair of the curved arcs ofthe scallop shaped recess 112 a, 112 b.

In some embodiments, the post 302 has a plurality of grooves 306 on aside face thereof, and the fixation device further comprises a washer340 having a ridge 342; the method further comprises: inserting thethreaded bolt 330 through the washer 340, wherein the step of placingthe threaded bolt 330 through the slot 307 in the post 302 includesengaging one of the grooves 306 with the ridge 342.

The fixation devices 330, 350 are secured by tightening, so as to securethe engaged wire 412 to the circular fixator. In some embodiments, thesecuring includes tightening a head 332 or a nut 334 of at least one ofthe fixation devices 330 using a ratcheting wrench 600 having a socketmember 602 with an open end 603 in the socket member to fix the fixationdevice 330; and passing the wire 412 or pin 350 through the open end 603of the socket 602 after the tightening to remove the wrench.

Once the wires 412 and/or pins 350 are inserted, the leg positioners200, 230, 250 are removed. The side leg positioners 230, 250 are removedby loosening the corresponding nuts 252 from the mounting devices 257,and releasing the positioners 230, 250. The removal of the legpositioner assembly 200 includes retracting each support device 204, 206until the corresponding neck portion 207 n of the corresponding arm 207is aligned in between the retaining members 221; and sliding the supportmembers 204, 206 out through the passage 205 between the retainingmembers in a direction perpendicular to the direction of the retraction(and parallel to the front face 201 a of the body 201 of the legpositioner assembly 200. Once the support members 204, 206 are removed,the body 201 of the leg positioner assembly 200 can be removed byunscrewing the knob 218.

In some embodiments, following insertion of at least one wire 412 or pin350, a first sponge or other dressing (not shown) is held at a firstwound site of the patient using a first clip 500 having a longitudinalslot 501 in a side surface of the first clip 500 for receiving andgripping the wire 412 or pin 350 to position the sponge.

The first clip 500 has a flat surface 510 at a first end thereof forengaging the sponge with a longitudinal axis 520 of the first clip 500approximately normal to a tissue of the patient at the first wound site.The first clip 500 has an angled surface 511 at a second end oppositethe first end, and the method further comprises: holding a second sponge(not shown) at a second wound site of the patient using a second clip500 for receiving and gripping a second wire 412 to position the secondsponge. The second clip 500 is identical to the first clip. The angledsurface 511 of the second clip engages the second sponge with alongitudinal axis 520 of the second clip at oblique angle relative to atissue of the patient at the second wound site.

In some embodiments, the first clip has first and second tubulargripping surfaces 503, 504 within the longitudinal slot. The at leastone wire 412 is gripped by the first tubular gripping surface 503. Thesecond tubular gripping surface 504 has a different size from the firsttubular griping surface 503. The second wound site has a half pin 350 ora second wire 412 inserted therein, the half pin 350 or second wire 412has a different diameter from the at least one wire, and the half pin350 or second wire is gripped by the second tubular gripping surface 504of the second clip.

In some embodiments, a rocker plate can be coupled to the ring 102 tosupport the circular fixator 100, 700. FIGS. 41-43 illustrate oneembodiment of a rocker plate 800 configured to couple to the ring 102 ofa circular fixator 100, 700 as described herein. The rocker plate 800includes a frame 802 having a closed end 806 a and an open end 806 b. Insome embodiments, the frame 802 has an elongated, semi-circular (orhorseshoe) design, although it will be appreciated that the frame 802can have any suitable shape. Although a single frame rocker plate 800 isillustrated, it will be appreciated that the rocker plate 800 cancomprise one or more unconnected frame components, such as, for example,a first frame component and a second frame component. The rocker plate800 is configured to fit multiple sizes of circular fixators 100, 700.

In some embodiments, the frame 802 defines one or more slots 804, 810extending from a top surface into the frame 802. For example, the frame802 illustrated in FIGS. 41-43 has a first slot 804 and a second slot810. In some embodiments, the slots 804, 810 are T-slots having an upperportion 812 having a first width and a lower portion 814 having a secondwidth greater than the first width. Although embodiments are illustratedherein including T-slots, it will be appreciated that the slots 804, 810can include any suitable shape configured to allow movement of a slider820 within the slot 804, 810. In some embodiments, the slots 804, 810are sized and configured to allow movement of the slider 820 within theslot but prevent rotation of the slider 820.

In some embodiments, the slots 804, 810 are sized and configured toreceive a plurality of sliders 820 therein. The slots 804, 810 arecoupled to an opening 808 a, 808 b at each end of the frame 802. Theopenings 808 a, 808 b are sized and configured such that the pluralityof sliders 820 can be inserted into the T-slots 804, 810 through theopenings 808 a, 808 b. FIG. 44 illustrates one embodiment of a slider820. Each of the sliders 820 includes a slider portion 822 coupled to asupport portion 824 by a first elongate shaft 826. The slider portion822 has a diameter less than or equal to the second width of the lowerportion 814 of the T-slots 804, 810 but greater than the first width ofthe upper portion 812. In some embodiments, the slider portion 822comprises a disc (slider plate) sized and configured to slide within thelower portion 814 of the T-slot. The first elongate shaft 826 has adiameter less than the diameter of the upper portion 812, and extendsfrom the slider portion 822 through the upper portion 812 and above thetop surface of the frame 802 when the slider 820 is inserted into theslot 804, 810. The slider 820 can be slideably moved within the T-slots804, 810 to position the rocker plate 800 and/or the sliders 820 withrespect to a bottom ring 102 of a circular fixator 100, 700.

In some embodiments, the first elongate shaft 826 includes a pluralityof threads sized and configured to receive a nut 828. The nut 828 can betightened to fix the slider 820 in place with respect to the rockerplate 800. In some embodiments, the T-slot 804, 810 allows the slider820 and/or the rocker plate 800 to be positioned with respect to thecircular fixator 100, 700. In some embodiments, one or more spacers (notshown) can be positioned between the nut 828 and the frame 802 and/orthe nut 828 and the support portion 824. The spacers can increase aspacing between the rocker plate 800 and a circular fixator 100, 700coupled thereto.

The support portion 824 is sized and configured to interface with andsupport the bottom ring 102 of the circular fixator 100, 700. A secondelongate shaft 830 extends from a proximal end of the support portion824. The second elongate shaft 830 is sized and configured to extendthrough a slot 104, 110 formed in the lower ring 102 of the circularfixator 100, 700. In some embodiments, the second elongate shaft 830includes a plurality of threads. The plurality of threads are configuredto receive a nut thereon (not shown) to couple the rocker plate 800 tothe circular fixator 100, 700.

In some embodiments, a sole 840 is coupled to a bottom edge of therocker plate 800. The sole 840 comprises a molded and/or machined coverthat extends from a bottom surface of the rocker plate 800 at leastpartially over each of the side walls of the rocker plate 800. The sole840 can comprise any suitable material, such as, for example, a plasticmaterial, a rubber material, a composite material, and/or any othersuitable material. The sole 840 can include an overmolded and/or amachined sole attached to the frame 802. The sole 840 does not extendover the openings 808 a, 808 b or the slots 804, 810 and does notinterfere with movement of the sliders 820 within the T-slots 804, 810.In some embodiments, the sole 840 includes a non-slip surface.

FIG. 46 illustrates one embodiment of a rocker plate 900 having aplurality of scallop-shaped recesses 852 a, 852 b formed thereon. Theplurality of scallop-shaped recesses 852 a, 852 b are formed about theperiphery of the T-slots 804, 810. The scallop-shaped recesses 852, 852b are similar to the scallop-shaped recesses 106 a, 106 b formed in thering 102 and prevent slipping of the slider 820 relative to the T-slots804, 810. The scallop-shaped recesses 852 a, 852 b prevent movement orslippage of the rocker plate 800 with respect to the lower ring 102.

FIG. 47 illustrates one embodiment of the rocker plate 900 coupled to anembodiment of the circular fixator 100. The rocker plate 900 includes aplurality of sliders 820 inserted into the T-slots 804, 810 formedtherein. The bottom ring 102 of the circular fixator 100 is supported ata predetermined spacing by the support portion 824 of each of thesliders 820. The predetermined spacing can be adjusted to accommodatepatients with varying foot sizes. The second elongated shaft 830 of eachof the sliders 820 extends through the slots 104, 110 formed in the ring102. A nut 854 is threadably coupled over a proximal end of the elongateshaft 830 to maintain the circular fixator 100 and the rocker plate 900in a fixed position.

In some embodiments, a securing bar 960 is coupled to a proximal end ofthe rocker plate 900. The securing bar 960 maintains the first andsecond ends of the rocker plate 900 at a fixed spacing and prevents thefirst and second ends of the rocker plate 900 from twisting or expandingduring an operation. In some embodiments, the securing bar 960 ispositioned to prevent the sliders 820 from sliding out of the T-slots804, 810 formed in the frame 802. For example, as shown in FIG. 47, insome embodiments, the securing bar 960 effectively covers the openings808 a, 808 b formed in the slots 804, 810, preventing the sliders 820from sliding out of the T-slots 804, 810. In some embodiments, a pin(not shown) is inserted into the openings 808 a, 808 b to prevent thesliders 820 from sliding out of the slots 804, 810.

Although the subject matter has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be construed broadly, to include other variants and embodiments,which may be made by those skilled in the art

What is claimed is:
 1. A rocker plate assembly, comprising: a bodyhaving a closed end and an open end, wherein the body includes a firstside member having a first end, a second side member having a secondend, and a connecting portion attached to the first side member oppositethe first end and attached to the second side member opposite the secondend, wherein the first and second side members each have at least oneslot extending from a top surface of the body into the body, and whereinthe first end of the first side member and the second end of the secondside member define the open end of the body; a sole having a bottomedge, a first sidewall, and a second sidewall, wherein the sole iscoupled to a bottom surface of the body, and wherein the first andsecond sidewalls extend at least partially over sidewalls of the body; asecuring member attached to the first and second ends of the body, thesecuring member covering openings of the slots, so as to prevent thesliders from sliding out of the slots; and a plurality of slidersslidably retained in the slots of the first and second side members. 2.The rocker plate assembly of claim 1, wherein the at least one slotcomprises a T-slot.
 3. The rocker plate assembly of claim 2, wherein atleast one of the plurality of sliders comprises: a slider plate receivedby a bottom of the T-slot, a first shaft attached to the slider plateand slidable and rotatable within a top portion of the T-slot, and asupport portion attached to the first shaft.
 4. The rocker plateassembly of claim 3, wherein the at least one of the plurality ofsliders further comprises: a second shaft attached to the supportportion, the second shaft offset from the first shaft.
 5. The rockerplate assembly of claim 1, wherein the plurality of sliders areconfigured to couple the rocker plate to a circular fixator.
 6. Therocker plate assembly of claim 1, wherein the sole comprises plastic orrubber.
 7. The rocker plate assembly of claim 1, wherein the top surfaceof the body includes a plurality of scallop-shaped recesses adjacenteach side of each of the slots.
 8. A rocker plate assembly, comprising:a unitary U-shaped body including: a first side member having a firstend, a second side member having a second end, and a curved connectingportion integrally attached to the first side member opposite the firstend and attached to the second side member opposite the second end,wherein the first and second side members each have at least oneT-shaped slot extending from a top surface of the body into the body;and a sole having a bottom edge, a first sidewall, and a secondsidewall, wherein the sole is coupled to a bottom surface of the body,and wherein the first and second sidewalls extend at least partiallyover sidewalls of the body; a securing member attached to the first andsecond ends of the body, the securing member covering openings of theslots, so as to prevent the sliders from sliding out of the slots; aplurality of sliders, each having: a slider plate slidably retained in arespective bottom of a respective one of the T-shaped slots of the firstand second side members, a first shaft slidably retained in a respectivetop of the respective one of the T-shaped slots of the first and secondside members, a support portion attached to the first shaft, and asecond shaft attached to the support portion, the second shaft offsetfrom the first shaft.
 9. The rocker plate assembly of claim 8, whereinthe sole comprises plastic or rubber.
 10. The rocker plate assembly ofclaim 8, wherein the top surface of the body includes a plurality ofscallop-shaped recesses adjacent each side of each of the slots.
 11. Therocker plate assembly of claim 8, wherein the first shaft is threaded,the assembly further comprising a first nut threadably received on thefirst shaft for gripping a respective one of the side members betweenthe first nut and the slider plate.
 12. The rocker plate assembly ofclaim 11, wherein the second shaft is threaded, the assembly furthercomprising a second nut threadably received on the second shaft forgripping a ring of a circular fixator between the second nut and thesupport portion.
 13. A fixation system, comprising: a plurality ofrings, each ring having a first face, a second face, and at least oneslot penetrating from the first face to the second face; a plurality ofmembers joining each one of the plurality of rings to an adjacent one ofthe plurality of rings; a rocker plate including a first side memberhaving a first end, a second side member having a second end, and aconnecting portion attached to the first side member opposite the firstend and attached to the second side member opposite the second end,wherein the first and second side members each have at least one slotextending from a top surface of the body into the body, a sole having abottom edge, a first sidewall, and a second sidewall, wherein the soleis coupled to a bottom surface of the body, and wherein the first andsecond sidewalls extend at least partially over sidewalls of the body,and a securing member attached to the first and second ends of therocker plate body, the securing member covering openings of the slots ofthe first and second side members, so as to prevent the plurality ofsliders from sliding out of the slots of the first and second sidemembers; and a plurality of sliders slidably retained in the slots ofthe first and second side members, each slider having a first shaftreceived by a respective one of the slots of the first or second sidemembers and a second shaft received by one of the at least one slot of abottom one of the plurality of rings, wherein the second shaft is offsetfrom the first shaft.
 14. The fixation system of claim 13, wherein eachof the plurality of sliders further comprises a support portion, thefirst shaft attached adjacent a first end of the support portion, andthe second shaft attached adjacent a second end of the support portion.15. The fixation system of claim 14, wherein: the slots of the first andsecond side members are T-shaped, each of the plurality of slidersfurther comprises a disc and a nut, each disc is received in a bottom ofa slot of a respective one of the first or second side member, and thefirst and second side members are gripped between the disc and nut ofeach respective slider.